[KDE] On resuming from sleep the external monitor is activated alone, and the laptop screen stays completely black

Hello,

I'm using a thinkpad as a workstation, with a dual-display configuration: the laptop screen and a big external screen.
The screen is directly connected to the laptop hdmi port, because using it through the thunderbolt port is hit-and-miss, but this is another story.

When I wake my system on after a night sleep, more often than not - it's not systematic -, my primary screen - the bigger external Dell monitor - is activated alone, and the laptop screen stays completely black.

I have to go to system settings -> Display to activate it again.

thanks for your support

/Bruno Hivert

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: xorg 1:7.7+19ubuntu14
ProcVersionSignature: Ubuntu 5.10.0-1033.34-oem 5.10.41
Uname: Linux 5.10.0-1033-oem x86_64
NonfreeKernelModules: nvidia_modeset nvidia
.proc.driver.nvidia.capabilities.gpu0: Error: path was not a regular file.
.proc.driver.nvidia.capabilities.mig: Error: path was not a regular file.
.proc.driver.nvidia.gpus.0000.01.00.0: Error: path was not a regular file.
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.suspend: suspend hibernate resume
.proc.driver.nvidia.suspend_depth: default modeset uvm
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86_64 Kernel Module 460.80 Fri May 7 06:55:54 UTC 2021
 GCC version: gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)
ApportVersion: 2.20.11-0ubuntu27.18
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CasperMD5CheckResult: skip
CompositorRunning: None
CurrentDesktop: KDE
Date: Wed Jul 7 07:48:20 2021
DistUpgraded: Fresh install
DistroCodename: focal
DistroVariant: ubuntu
DkmsStatus:
 acpi-call, 1.1.0, 5.10.0-1034-oem, x86_64: installed
 nvidia, 460.80, 5.10.0-1033-oem, x86_64: installed
 nvidia, 460.80, 5.10.0-1034-oem, x86_64: installed
 nvidia, 460.80, 5.8.0-59-generic, x86_64: installed
ExtraDebuggingInterest: No
GraphicsCard:
 Intel Corporation UHD Graphics [8086:9bc4] (rev 05) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Device [17aa:22c0]
 NVIDIA Corporation Device [10de:1f95] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Device [17aa:22c0]
InstallationDate: Installed on 2021-05-21 (46 days ago)
InstallationMedia: Kubuntu 20.04.2.0 LTS "Focal Fossa" - Release amd64 (20210209.1)
MachineType: LENOVO 20TK001JUS
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.10.0-1033-oem root=/dev/mapper/vgkubuntu-root ro
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/15/2021
dmi.bios.release: 1.15
dmi.bios.vendor: LENOVO
dmi.bios.version: N2VET30W (1.15 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20TK001JUS
dmi.board.vendor: LENOVO
dmi.board.version: SDK0T08861 WIN
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.ec.firmware.release: 1.8
dmi.modalias: dmi:bvnLENOVO:bvrN2VET30W(1.15):bd04/15/2021:br1.15:efr1.8:svnLENOVO:pn20TK001JUS:pvrThinkPadX1ExtremeGen3:rvnLENOVO:rn20TK001JUS:rvrSDK0T08861WIN:cvnLENOVO:ct10:cvrNone:
dmi.product.family: ThinkPad X1 Extreme Gen 3
dmi.product.name: 20TK001JUS
dmi.product.sku: LENOVO_MT_20TK_BU_Think_FM_ThinkPad X1 Extreme Gen 3
dmi.product.version: ThinkPad X1 Extreme Gen 3
dmi.sys.vendor: LENOVO
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.102-1ubuntu1~20.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 20.2.6-0ubuntu0.20.04.1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.nvidia-graphics-drivers: nvidia-graphics-drivers-* N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.9-2ubuntu1.2~20.04.2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200226-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1